This document relates to wireless communications.
Wireless communication systems can include a network of one or more base stations to communicate with one or more wireless devices such as a mobile device, cell phone, wireless card, mobile station (MS), user equipment (UE), access terminal (AT), or subscriber station (SS). Each base station can emit radio signals that carry data such as voice data and other data content to wireless devices. A base station can be referred to as an access point (AP) or can be included as part of an access network (AN).
Radio stations such as wireless devices and base stations can use one or more different wireless technologies for communications. Various wireless technologies examples include Code division Multiple Access (CDMA) such as CDMA2000 1x and its enhancement networks, High Rate Packet Data (HRPD), Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA), Long-Term Evolution (LTE), and Worldwide Interoperability for Microwave Access (WiMAX).
Some wireless technologies can specify a minimum transmission unit in the physical layer as being one frame. In some wireless technologies, the duration of a frame is 20 ms. For example, a base station can transmit user data in a frame over a forward link fundamental channel (F-FCH) based on a fixed modulation rate such as 9,600 kbps. A mobile station can use a baseband receiver to receive a signal from a base station.